The Indian Institutes of Technology (IITs) are likely to blacklist about 20 startups and ecommerce companies this placement season for having reneged on offers made to graduating students last year.

Apart from this, a warning will be issued to companies that deferred joining dates, changed job profiles or altered salary terms. Ecommerce company Flipkart will get a warning letter for deferring the date of joining for its IIT hires last year.

“Flipkart does not figure in the list of startups that would face a blanket ban as it did not completely withdraw the offers,” said All-IIT Placement Committee (AIPC) convenor Kaustubha Mohanty, who added that a ban on Zomato will remain in place for a second year. The companies couldn’t be reached for comment on Sunday.

The IITs will draw up the list in about two weeks, it was decided at the AIPC meeting on Saturday. “We do not want this to be repeated this year,” said a faculty member.

Mohanty declined to give details on the companies likely to be on the blacklist. “IITs are unanimous that this kind of behaviour will not be tolerated,” he said.

Twelve IITs were present at the AIPC meeting at IIT Kanpur to discuss placements for 2017. Of the big ones, IIT Bombay didn’t attend, Mohanty said.

The meeting decided that the startups would be grouped into three — those that deferred placements, those that cut pay or changed job profiles and those that withdrew offers.

The warning letters will go to the companies on the first two lists while those on the third would be barred, Mohanty said. Zomato had been banned last year after a spat over placement slots. CEO Deepinder Goyal then took to Twitter to express his views on the matter.

Flipkart told campus recruits last year it was deferring joining dates to December from June due to a restructuring exercise.

“The decision to defer joining for six months has been taken after due evaluation of all possibilities and keeping in mind timelines to complete organisational restructuring at Flipkart,” the company said at the time. “We are committed and absolutely confident of having all our trainees on board in December 2016.”